Cholesterol are packaged in entities called lipoproteins - Different lipoproteins depending on their density - Lipoproteins : LDL, HDL, etcetc - LDL: Low Density Lipoprotein bad cholesterol - LDL receptors: molecules on the surface of cells that receives packages of cholesterol - HDL: High density Lipoprotein good cholesterol - Sometimes these LDL receptors may be full, and the LDL dumps its cargo (cholesterol), the HDL picks it up and brings it back to the liver and eliminate it - Small particle LDL are more problematic as they can easily penetrate the endothelium lining in blood vessels which causes damage and plaque - Size can be indicated using a nuclear magnetic resonance spectrometer - Their view is that the atherosclerotic culprit is not LDL, particle numbers, but the size of those particles
- Research is showing that it is not total amount of cholesterol carried by LDL particles that matters but the number of small LDL particles in the bloodstream. This might turn out to be the best predictor of heart disease. Heart Attack: - Occurs when the plaque bursts open inside the coronary arteries because the body perceives it as a site of damage, blood cells will try to curb the damage by forming a clot. This clot can block the blood flow resulting in a “heart attack” - Plaque will burst if there is inflammation - Measure can be carried out called high sensitivity C-reactive protein - When the is less than 2mg/L, then the risk of heart disease decreases ★ Lesson 3: Diet and the Heart II Video 1: Cholesterol Levels - Does high blood cholesterol cause coronary disease? - Will reducing blood cholesterol reduce the risk? - At what cholesterol level should dietary or drug treatment be started? - The best way to study these question is to do intervention studies - Study: MRFIT After 7 years intervention group reduced saturated fat intake by 30% and increased polyunsaturates by 33% Difference in blood cholesterol was 3% - Study: The Lipids Research Clinics Coronary Primary Prevention Trial (CPPT) 3806 high risk men aged 35-59 healf treated with diet, half treated with diet + cholestyramine Blood cholesterol decreased by 9% and heart attack decreased by 19% For every 1% decrease in cholesterol the risk of heart disease is decreased by 2% Have to treat 67 men aggressively to save one cardiac event - JUPITER Study: 100% reduction in cardiovascular events in men who were at risk because they had high C-reactive protein levels
Have to treat 120 people to prevent 1 event Very costly Reduces inflammation - Cholesterol measured by blood test - Cholesterol mmol/L = mg/Dl x 0.026 - Triglycerides mmol/L = mg/Dl X 0.0113 - Total cholesterol Under 200 (5.2) desirable 200-239 (5.2-6.2) Borderline More than 240 (6.2) High - Total LDL Under 130 (3.4) Desirable 130-159 (3.4-4.1) Borderline More than 160 (4.1) High - Total HDL Less than 40 (1.0) Undesirable Greater than 60 (1.56) Desirable - Total Triglycerides Under 200 (2.26) Desirable 200-400 (2.26-4.52) Borderline Greater than 400 (4.52) Undesirable - Low Risk: LDL/HDL < 3 Total cholesterol/HDL < 4 -
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- Spring '11
- Nutrition, Atherosclerosis